Green’s Dictionary of Slang

a tall, thin person.

1830		Lytton Paul Clifford III 57: ‘The next was an old maid of quality [...] as lean as a lawyer.’ [...] ‘And you very wittily called her a hop-pole!’.
1850		F.E. Smedley Frank Fairlegh (1878) 13: I was tall for my age, but slightly built, and so thin, as often to provoke the application of such epithets as ‘hop-pole,’ ‘thread-paper,’ &c.